A passenger conveyor (such as an escalator or a moving walkway) is increasingly widely used in public places such as subways, shopping malls, and airports, and operation safety thereof is increasingly important.
During movement, steps of the passenger conveyor may bounce due to some reasons, causing damage to the steps or even risks to passengers thereon. The step bouncing problem may occur due to abnormal operation of the step roller as a guide rail is deformed, or a guide rail joint is not flat, or a foreign matter is stuck in an operation trajectory, and phenomena such as step bouncing, upthrusting or sagging at the corresponding trajectory may occur. Therefore, normal operation of the step roller is one of the essential conditions for ensuring safe operation of the steps.